Sewing mechanism



July 29, 1941; s.'w. AVIS SEWING MECHANISM Filed 00* 14, 1958 7 Sheets-Sheet 1 J I l I II Ln INVEN+D -Y SBJMW A a July 29, 1941. s. w. AVIS smwm MECHANZQESM I Filed Oct. 14, 1938 7 sheets-sheet 2 lwvard-maz July 29, 1941. s. W.-AVlS SEWING MECHANISM Filed Oct. 14, 1938 7 Sheets-Sheet 3 y 1941- s. w. AVIS 2,250,696

SEWING MECHANISM Filed Oct. 14, 1938 7 Sheets- Sheet 4 y 1941- s. w. AVIS v I 2,250,696

SEWING MECHANI SM Filed Oct. 14, 1938 V 7 Sheets-Sheet 5 INVEN+U I V w- -H- s- July 29, 1941. s, AWS 2,250,696-

SEWING MECHANISM Filed Oct. 14, 1938 '7 Sheets-Sheet 6 g '1 m i I 1.: ,alfi 22.5 f I INVEIir /70 /6/ y -we,ceww

July 29, 1941. s, w v s 2,250,696

SEWING MECHANISM Filed Oct. 14. 1938 7 Sheets-Sheet 7 ylauii PM INVEN+ U Patented July 29, 1941 SEWING MECHANISM Samuel W. Avis, Providence, B. 1., asslgnor to The Reece Button Hole Machine Company, Boston, Mass., a corporation of Maine Application October 14, 1938, Serial No. 235,012

. e 11 Claims. This invention'relates to sewing machines and 4 more particularly to novel mechanism in a sewing machine for coordinating the thread handling element thereof with a reciprocating and laterally moving needle for constant cooperation.

It is the primary aim and object of the present invention to provide novel mechanism for constantly coordinating a. laterally immovable, rotating thread-handling element with a reciprocating and laterally vibrating needle such that the loop-seizing portion of said element seizes each loop which is cast by the needle on slight recession from either of its different lowermost positions.

It is another object of the present invention to provide for adjustment of the novel mechanism so that the thread-handling element will seize each cast loop in spite of selective variation of the amplitude of the needle vibration.

It is another object of the present invention to make provisions in the mechanism for additional constant coordination of the thread-handling element with the needle in accord with a second lateral movement of said needle transversely to the plane ofoscillation of the latter so that the thread-handling element will seize each loop on being cast by the needle in any'- of its various positions of operation.

It is another object of the present invention to provide for another adjustment of the mech anism so that the thread-handling element will seize each cast loop in spite of selective variation Fig. 2 is a front elevation, partly in section, of themachine shown in Fig. 1. I

Fig. 3 illustrates one example of the type of sewing accomplished with the present machine.

Fig. 41s a fragmentary section taken substantially on the line 4-4 of Fig. 1.

' Fig. 4a is a diagrammatic illustration of ,a modification of part of the operating structure shown in Fig. 4.

Fig. 5 is a fragmentary section takenv substantially on-the line 5-5 of Fig. 1.

Fig. 6 is a fragmentary perspective view of the operating structure disclosed in Figs. 4 and 5.

Figs. 7 to 10, inclusive, diagrammatically illustrate progressive steps in one cycle of operation of a needle, a rotary shuttle and a bobbin retainer, for the formation of a lock stitch.

Fig. 11 is a plan view of a shuttle.

Fig. 12 is an enlarged, fragmentary longitudinal section through a part of the machine disclosedin Fig. 1, showing, however, a rotary looper instead of a rotary shuttle.

Fig. 13 is a front elevation of the structure disclosed in Fig. 12.

Fig. 14 is a fragmentary section taken substantiallyalong the.line l4-|4 of Fig. 12.

Fig. 15 is a perspective view of a rotary looper. Figs. 16 to 21, inclusive, diagrammatically illustrate progressive steps in one cycle of operation of a needle, a rotary looper and a loop deflector, for the formation of a chain stitch.

of the extent of said second lateral movement of the needle.

It is also among the objects of the present invention to provide a drive for operating either a bobbin case retainer for use with a shuttle, or a loop deflector for use with a looper.

Before explaining-in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodimentsand of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

In the drawings: Fig. 1 is a longitudinal section through a sewing machine which embodies the present inven-- tion.

Referring to the drawings and more particularly to Fig. 1, the present machine comprises a main frame 30 on which are suitably mounted a head 3| and a work table 32. A needlebar is axially slidable in a sleeve 34 which is mounted in the head 3| for rotation about the axes of the transverse pivots 36 and 31, and serves as a fulcrum for saidneedle bar for oscillation in any direction. The needle bar 35 carries a needle 49.

Mounted in bearings 40 and 4| in the head 3| is a needle crank shaft 42 which carries a pulley 43 and a gear 44 at one end, and abalanced crank 45 at the other end. The shaft 42 may be driven from any suitable Prime mover (not shown) by means of a belt 43a which is guided over the pulley 43. The crank 45 has any suitable driving connection 46, 41 and 48 with the nedle bar 35 of such-construction that the latter is reciprocated on rotation of the crank shaft v42, without interfering with any oscillatory movements of said needle bar.

Rotatably mounted in suitable bearings, provided by the head 3| and a lug 50 of a bracket 5| in the machine frame 30, respectively, is a vertical shaft 52 on which is mounted a disk 53, having cam grooves 54, 55 and 56 in its opposite faces (Figs. 1, 4 and 5). The crank shaft 42 is provided with a worm 51 which is in permanent mesh with a worm gear 58 on the cam shaft 52 for driving the latter.

Pivotally mounted at 68 in the machine frame 38 is a block 6|, having a groove 62 in which a longitudinally movable bar 63 is guided. Secured to one end of this bar 63, hereafter called the "needle-oscillating bar is a sleeve 64 in which the needle bar 35 is axially slidable. The sleeve 64 is rotatable about the axes of transverse pivots 65 and 66. Hence, the needle bar may be oscillated in any direction about its fulcrum 34 upon longitudinal movement of the needle oscillating bar 63 and/or rocking movement of the same about the pivot axis of the guide block 6|. The other end of the bar 63 is provided with a longitudinally disposed guideway 25 (see particularly Figs. 4 and 6), which receives one end of a stud 61, carried by a link 68. The other, rectangular end 61a of the stud'61 (see particularly Fig. l) is received in a guideway 26, provided in a head 21 which has its shank 28 pivoted in a bracket 29 in the head 3|. The guideway 26 permits lateral movement of the stud 61 substantially in the direction of the arrow 26a (Fig. 4) and, consequently, oscillation of the bar 63, while holding said stud 61 practically immovable in the direction 2617 (Fig. 4). The guideway 25, therefore, permits longitudinal movement of the needleoscillating bar 63 relative to the stud 61 as hereinafter more. fully explained. The-other end of the link 68 carries a bolt 69, having its T-head 69a slidably received in an arcuate groove 18 of a lever 1| (Figs. 2 and 4). A nut 69b cooperates with the bolt 69 to lock the link 68 to the lever 1| in any desired position of said bolt within the confines of the arcuate groove 18. Lever 1| is rotatably mounted on a pivot 12 which is carried by a boss 13 of the head 3| (Fig. 1). The lever 1| has an arm 14 which carries a follower 15, cooperating with the cam groove 54 in the disk 53 (Fig. 4). The arcuate groove 18 in lever 1| is disposed concentrically of the pivot 61 when the needle oscillating bar 63 and the cam disk 53 assume the home or rest position illustrated in Fig. 4. It is then possible to. rock the link 68 about the pivot 61 so that the bolt 69 may assume any desired position within the arcuate groove 18, without rocking bar 63 about its pivot 68. Clockwise rotation of the cam disk 53 as viewed in Fig. 4 will cause oscillation of the bar 63 about the pivot 68 of theguide block 6| through intermediation of cam groove 54, lever 1| and link 68, thereby imparting oscillatory movements to the needle bar 35 in a plane at right angles to the longitudinal axis of said bar 63. By adjusting link 68 such that the bolt 69 is in coaxial alinement with the pivot 12, no oscil'latory movements are imparted to thebar 63 in spite of oscillation of the: lever 1|.

Rotatably mounted in a tubular extension 16 of the bracket 5| (Figs. 1, 5 and 6) is a vertical shaft 11 on the upper end of which are mounted two levers 18 and 19 (Fig. 4). Lever 18' carries a follower 8| which cooperates with the cam in Fig. 4, the needle oscillating bar 63 is moved longitudinally through intermediation of cam groove 55, levers 18 and 19, link 83, pivot 84 and arm 85. Due to the substantially spiral design of the cam groove 55 as shown in Fig. 4, a comparatively slow longitudinal motion in one direction is imparted to the bar 63, followed by a rather sudden return motion of said bar as caused' by the retum" groove portion 55a and a spring 81 which constantly urges the lever 18 inwardly toward the cam shaft 52. It can now be understood that on rotation of the cam disk 53, the needle bar 35 is oscillated in two planes which are transverse to each other, and that the drives therefor are separate units which operate independently of each other.

Referring now to Figs. 1, 5 and 6, the horn 94 of the machine, formed by a forwardly extending part of the machine frame 38 and the work table 32, has mounted therein a bracket 95 which supports the cam block 96 of a combined support and drive 91 for either a rotary shuttle or a rotary looper. This combined support and drive 91 is disclosed in, and forms the subject matter of, my copending application Serial No. 185,538, filed January 18, 1938.

More particularly, the cam block 96 is non-rotatable, but axially slidable, in the bracket 95 and has a continuous cam surface 98 with which cooperate a plurality of angularly spaced pawls 99, pivoted at I88 on a carrier sleeve |8| which is rotatably mounted in said cam block 96. An annular shoulder of the carrier sleeve IN is retained in permanent engagement with a similar shoulder of the cam block 96 as indicated at I82 by means of a collar I84 which abuts said cam block, thus preventing axial movement of the carrier sleeve I8| relative to the cam block 96. The pawls 99 have depending fingers 5 and are so operated by the cam surface 98 that these fingers enter correspondingly formed apertures 6 in the periphery of a rotary shuttle or a rotary looper to support the same at all times, yet permit either the passage of a non-twisted loop of needle thread completely around the shuttle, or the complete passage of the looper through said loop, all as described in my above-mentioned. copending application.

The carrier sleeve MI is mounted on one end of a shaft 8 which has-its other end journalled in a bearing III, provided by the bracket 5| (Fig. 1). Mounted in any suitable manner on the shaft 8 are two spaced collars 2 (Figs. 5 and 6), forming an annular groove 3 into which projects a roller 4 of a shifter fork II5 which is mounted on the shaft 11 for rotation therewith. Hence, on rotation of the cam disk 53 in clockwise direction as viewed in Fig. 4, the cam groove 55 effects also axial movement of the shaft I I8 and of the combined support and drive 91 which is carried thereby. v

The shaft H8 is driven in the following man ner. Splined at I28 on the shaft 8 is a gear groove 55, and lever 19 is connected at 82 with a link 83. Link 83 is also pivotally connected I21 of a comparatively wide periphery which is in constant mesh with another gear I22, splined at I23 on an axially immovable counter shaft I 24 which is mounted in bearings I25 and I26, provided by a bracket I 21 in the horn 94 of the machine and other suitable structure carried by the machine frame 38, respectively. One end of the counter shaft I24 carries a gear I28 which is in permanent driving relation with the gear 44 on the needle crank shaft 42 (Fig. 1) through intermediation of a suitably journalled idler gear I29. In order to prevent axial movement of the gear I2I together withthe shaft IIO, a member I30 which is secured to the bracket I2I retains said gear in permanent abutment with said bracket.

Gear I22 has a. sleeve-like portion I35 which is provided with an annular groove I36 wherein projects a stud I31, carried by one arm I38 of a bell crank lever I39 which is pivotally mounted at I40 on the bracket I2'I (Fig. 1). The other arm I of the lever I39 is pivotally connected at I42 with a link I43 which carries a bolt I44 (Figs. 2 and the T-head ofwhich is slidably received in an arcuate groove I45 in a lever I46 which is carried by one end of a shaft 1, rotatably mounted in a boss I49 of the bracket 5| (Figs. 2 and 5). A nut I44b cooperates with the bolt I44 to lock the link I43 to the lever I46 in any desired position of said bolt within the confines of the arcuate groove I45. Mounted on the other end of the shaft I41 is an arm I49,

carrying a follower I50 which is in permanent cooperation with the cam groove 56 in the lower face of the disk 53. This cam groove 56 (Fig. 5)

3 of the same in a plane at right angles to the needle crank shaft 42. However, since the shuttle I55 has to make approximately two revolutions to 7 each reciprocationof the needle so that the takeup device I59 (Fig. 1) may have'sufllcient time to perform its operation between the "casting of consecutive loops by the needle, the speed ratio between the gears and I26 (Fig. 1) is 1 to 2. Hence, the shuttle I55 makes approximately two revolutions to each single stroke of the gear I22, with the result that the two rotary speeds of said shuttle alternate after approximately each second revolution thereof. v

In Fig. '7, the needle 49 is sufliciently withdrawn from its one lowermost position 49', shown in brokenlines, to cast the loop I which will be presently seized by the beak I60 of the shuttle Ill while the same rotates in the direction of the arrow I62. On slight recession of the needle 45 from its next lowermost position 49' indicated in broken lines in Fig. 10; the next loop I is cast.

is of such shape that, on rotation of the disk 53, I

the gear I22 is reciprocated-on the counter shaft I24 through intermediation of levers I49 and I46, link I43 and lever I39. The gears I2I and I22 are spiral gears so that reciprocation of the gear I22 on the counter shaft I24 will cause slight rotations of the gear I2I in opposite directions by reason of the spiral mesh of the teeth of these gears. Hence, even though gear I22 is driven at uniform angular speed, it follows that the gear I2I has two alternatingspeeds, one being lower and the other higher than the uniform rotary speed of the gear I22, depending on the momentary direction of axial movement of the latter. The reason for rotating gear I2I at different rotary speeds will be explained hereafter.

The arcuate groove I45 in the lever I46 is disposed concentrically of the pivot I42 when said lever is in the home position shown in Fig. 5. Hence, when themachine is at rest, link I43 may be rocked about its pivot I42 and the bolt I44 may be adjusted in any desired position within the arcuate groove I45 without rocking the lever I39 and shifting the gear I22 from its home position. By adjusting the bolt I44 in the groove I45, the stroke of the reciprocating gear I22 and, hence, the two alternating speeds of the gear I2I, may be varied as desired. In adjusting the link During the time interval between the casting of the loops I and I, the shuttle I55 has been rotated through two revolutions plus an additional rotation through an angular distance corresponding to the acute angle between the shuttle beaks .160 in the positions shown in Figs. 7 and 10, so

with the pivot I" of the lever I46, the rocking motion of the latter is not transmitted to the lever I39, with the result that gear I22 is not reciprocated and gear I2I will be driven at uniform speed.

Referring now more particularly to Figs. 7 to 10, inclusive, there is shown a shuttle I in various positions. of cooperation with the vibrating needle 49. In order that the loop-seizing beak I of the rotary shuttle I55 may seize each loop of upper thread right after the same is cast by the needle 49 on slight recession from its alternately changing lowermost positions 49' and 49" (Figs. 7 and 10), it is evident that the rotary speed of the shuttle I55 has to alternate between relatively slow and relatively fast. This is accomplished by the spiral gears I2I and I22, the latter of which is reciprocated.

The cam disk 53 is so driven from the needle crank shaft 42,- and the cam grooves 54 and 56 are so coordinated, that the gear I22 is reciprocated once during two consecutive reciprocations of the needle 49 and during each lateral vibration 11) and rotatably supported therein with its hub that said beak I60 will seize the loop I immediately on formation of the same. The additional rotary motion of the shuttle I55 is caused on axial movement of the gear I22 in a certain direction relative to the gear I2I. Following this, the needle 49 will be swung back into the axial disposition shown in Fig. 7 and moved into the lowermost position 49', ready to cast the next loop I on slight recession from said lowermost position. During the time interval while the needle 49 recedes from the position shown in Fig. 10, swings into the axial disposition shown in Fig. '7, moves into the lowermost position 49' and slightly recedes from said lowermost position into the full line position, shown inFig. 7, the shuttle I55 has been rotated through two revolutions minus an angular distance corresponding to the acute angle between the shuttle beaks I60 in the positions shown in Figs. 10 and 7. This deductible slight rotation of the shuttle is caused by the axial movement of the gear I22 in the opposite direction relative to the gear I2I. Consequently, the shuttle beak I60 is again in a position to seize the loop I immediately after the latter is cast. It will now be understood that the shuttle I55 alternately assumes the momentary positions shown in Figst '7 and 10, i. e., positions in which its beak I60 will presently enter the loops I and I'.that are alternately cast by the vibrating needle" 49.

The distance between consecutive lock stitches, as formed by the vibrating needle 49 and cooperating shuttle I55, maybe varied by loosening-the nut 69b on the bolt 69, swinging the link 60 about its pivot 61 into another position, and retightening the nut 69b (Fig. 2) to thereby vary the amplitude of vibration of the needle 49 in a plane at right angles to the needle crank shaft 42. Corresponding adjustment of the bolt I44 on the link I43 in the arcuate groove I45 of the lever I46 will shuttle I55 will be in loop-seizing position every time the needle 49 casts the alternate loops I and I'. v

A bobbin I63, holding a supply of under thread, is rotatable in a bobbin case I64 which is located in an annular recess I61 of the shuttle I55 (Fig.

4- 2,2:so,eec

I65 on a pin I66, projecting from said shuttle. In order to retain the bobbin case in the shuttle and to prevent rotation of the same regardless of the rotary and axial motions of said shuttle, the following structure is provided. As best shown in Fig. l, the bracket 85 rotatably supports a rod I to which the hub I12 of a bobbin retainer I13 is keyed as at Hi. The retainer I13 is in form of a fork (Figs, 2 and 7 to 10, inclusive) and pref-- erably welded or otherwise secured to the hub I12. A spring I14 is suitably anchored at I15 to the retainer I13 and snapped into an annular groove I16 in the rod I10, thereby maintaining said retainer in keyed engagement with said rod. Manual removal of the retainer ,I13 from the rod I10 to permit reloading of the bobbin case is greatly facilitated in that the spring I14 needs to be merely snapped out of the annular groove I16 prior to removal of said retainer.

The bobbin case I64 is provided with an arcuate groove I11 which is concentric with respect to the axis of the rod I10 and receives depending fingers I18 (Fig. 1) of the retainer I13. More particularly, these depending fingers I18 are so angularly spaced that at least one of them projects into the groove I11 at any time when the retainer I13 is rocked by the rod I10. Secured in any suitable manner to the rod I10 is an arm I18, having a forked end I80 into which projects a crank pin I8I, adjustably mounted in a di- 8 ametrical groove I82 of a disk I83., The disk I83 is carried by a stub shaft I84 (Fig. 1) which is rotatably, but axially immovably, mounted in the bracket I21. Also mounted on the stub shaft I84 is a gear I85 which is in constant mesh with a gear I86 on the counter shaft I24. The ratio between these gears is 1 to 1. .Hence, during each revolution of the counter shaft I24, i. e., duringapproximately each revolution of the shuttle, the retainer I13 is oscillated once so that its fingers I18 move alternately out of the arcuate groove I11 in the bobbin case I64 in order to clear the non-twisted loop I or I which passes completely around the shuttle during approximately each second revolution of the latter. Figs. 8 and 9 illustrate the two angular positions of the retainer I13 in which either of the fingers I18 is momentarily withdrawn from the arcuate groove I11 to provide gaps I81 and I88, respectively, between the shuttle I55 and the fingers I18, through which the loop passes on its travel around the shuttle. The diametric groove I82 in the disk I83 may be dispensed with and the crank pin I8I may be made integral with said disk I83, in which case the eccentric throw of the pin I8I is so selected that the gaps I81 and I88 are sufliciently wide so as not to obstruct the free passage of a loop around the shuttle regardless of any variation of the amplitude of vibration of the needle and a corresponding variation of the alternating speeds of the shuttle.

As earlier explained, the needle bar 35 has a second oscillatory motion in a plane parallel to the axis of the needle crank shaft 42 and about the pivot 36 of the sleeve 34 as a fulcrum (Fig. 1). The cam groove 55 (Fig. 4), which causes this second oscillating motion of the needle bar 35, is so designed that the needle 48 retracts from the foremost position shown in Fig. 1' in a stepby-step motion for the purpose of producing the zigzag stitches I80 (Fig. 3) which cover the customary underlying stitches (not shown) of a tack. These underlying stitches of the tack may be produced by any conventional mechanism, which is not disclosed as the same does not form any part of the present invention. The stepby-step retraction of the needle 48 is participated in by the shaft III) and the thereby carried combined support and drive 81 of the shuttle, so that the latter may cooperate with the needle 48 during its step-by-step retraction. The gear I2I does not participate-in the step-by-step retraction of the shaft IIO, it being held axially immovable between the bracket I21 and the member I30. However, the rod I10 and the thereby carried bobbin retainer I13 and forked member I18 are moved together with the shaft H0 and shuttle I55 by means of spacers I8I (Fig. 1) which straddle said forked member I18 and are carried by a rod I82, suitably secured to the cam block 86 of the combined support and drive 81. Hence, the retainer I13 remains in permanent cooperation with the bobbin case I64 in the shuttle I55 regardless of the position of the latter during its step-by-step retraction. The crank pin I8I and the disk I83 are axially immovable, but the former is of such length as to remain in registry with the forked end I of the member I18 in spite of the movement of the latter to and from disk I83.

Also movable with the combined support and drive 81 on its step-by-step retraction is a throat plate I85 (Figs. 1 and 6) which is secured at I86 to the cam block 86 and has an elongated opening I81 through which the vibrating needle passes on each descent. The throat plate I85 is guided for linear movement in a longitudinal slot I88 in the work table 32, thereby also preventing rotation of the combined support and drive 81 in the bracket 85. The work W lies on the work table 32 and is pressed thereagainst by any conventional presser foot I88 so that the work W will not move with the throat plate I85. The presser foot I88 is preferably normally spring-urged toward the work table 32 and may be lifted in any conventional manner as, for instance, by a foot pedal (not shown).

Provisions are preferably-made for varying the length 2; of the tack (Fig. 3). To this end, the

modified construction in Fig. 4a shows that the lever 18 (Fig. 4) has been dispensed with and the lever 18 is pivotally connected at200 with one end of a link 20I which has its other end adjustably secured within the confines of an arcuate groove 202 of a lever 203 by means of a fork 1 which is preferably manipulated from the outside of the machine and suitably secured in any adjusted position. The lever 203, which is rotatably mounted on a suitably supported pivot 204, has an extending arm 205, carrying motion of the needle 48 may be varied, resulting in a different length of the tack. Link 20I may be so adjusted that its connection with the arcuate groove 202 is in coaxial alinement with the pivot 204, with the result that no motion is transmitted through the link 20I to the lever 18 in spite of oscillation of the lever 203.

While the preceding description had to do with the formation of lock stitches, the following description has to do with the formation of chain stitches in the same machine. It is thereby of particular advantage that the combined support and drive 91 may be used interchangeably, eithercombined support and drive 91 (Figs. 12 and 14) in such altemate fashion that the looper is at all times in supporting and driving engagement with the pawls 99, yet is allowed to pass completely through aloop without any interference from said pawls. More particularly, the pawls 99 are retracted from the looper as they approach and pass the loop. As best shown in Fig. 15, the looper 201 has its leading end 209 terminate in a loop-seizing beak 2I0, and has its trailing end 2 formed like a fork, the one leg 2I2 of which projects considerably beyond the front face 2I3 of the looper so that the space between the fork legs may be entered by the needle 49. The loop, which is cast by the needle 49 on slight recession from any of its lowermost positions, is seized by the beak 2I0 of the looper which thereupon passes completely through said loop. Before the looper leaves the loop, the latter has to pass around the forked looper end 2| l, whereby the loop is widened to suchan extent as to form, with the aid of a loop deflector 225 to be described hereafter, the thread triangle 2I4 shown in Fig. 16 through which the needle passes so as to form a chain stitch in a manner well known to those skilled in the art.

While the shuttle 155 makes approximately two revolutions to one reciprocation of the needle 49, the looper 201 makes approximately one revolution to each reciprocation of the needle. Consequently, in using the machine shown in Fig. 1 for the formation of chain stitches,the ratio between the gears 44 and I28 in the rear of the machine must be 1 to 1. Any suitable provisions may be made for replacing the gears 44 and I28 with new gears of a 1 to 1 ratio and for remes'hing the idler gear I29.with said new ears. By way of example, the idler gear I29 may be rotatably mounted on a tubular member 2l5 (Fig. 1) which telescopes with acylindrical portion 2I6 'of an arm 2" which is rotatably mountedon a bushing 2! in the machine frame 30. On reand taken up by the take-up device I58 (Fig. 1). Also, the needle 49 has descended to its one lowermost position 49' shown in broken lines in Fig. 17, and then receded into the full line position shown in this figure, thereby casting the loop I which will be presently seized by thebeak 2" of the looper. While the looper passes through the loop F, the deflector 225 is shifted to the right as viewed in Figs. 18 and 19 to engage and deflect the forward leg of said loop and form g a thread triangle by the time the forked looper end 2| I passes through the latter and the needle 49 enters said loop on its descent into its other lowermost position 49" (Fig. 19). Continued rotation of the looper into the position shown in Fig. 20 will, effect the release of the loop I from the looper, whereupon the take-up device I58 moving the screw 2I9, which extends through a lug 220 of the tubular member 2I5, from the tapped hole 22I in a machined-surface 222 of the machine frame 30, the idler gear I29 maybe swung from mating engagement with the gears -44 and I28 and the latter may then be replaced by preassigned gears of a 1 to 1 ratio. The idler gear I29 is then moved into mating engagement with the replaced gears and held in matingengagement therewith until the screw 2| 9 is secured in another'tapped hole 223 in the machined surface 222 of the machine frame 30 In Fig. 16, a loop I s shown in typical chainstitch concatenation with the loop forms the thread triangle 2. The needle. 49 is presently passing through the thread triangle 2 and between the legs of the forked looper end 2| I. The loop deflector 225 is holding the forward side 226 of the loop I in such position that the needle 49 may pass therethrough. During the slight further rotation of the looper 201 from the position shown in Fig. 16 into that shown in Fig. 17, the loop I has been cleared by the trailing and 2 of the looper and will be presently. withdrawn from the loop deflector 225 I which comes again into operation to withdraw said loop I from the deflector 225 and up against the work W. The next loop I which has just been cast by the needle 49 on slight recession from its lowermost position 49", is immediately seized by the beak 2 I0 of the looper 201 which then passes theret'hrough. The deflector 225 now swings in the opposite direction through the position shown in Fig. 21 and into the position shown in Fig. 16, in order to sweep the forward leg of the loop I to the left as viewed in Fig. 16 so that said loop may be entered by the needle 49 on its next descent into the lowermost position 49's In this fashion, a plurality of chain stitches is formed which may be arranged in the zigzag fashion shown in Fig. 3 to form the covering stitches of a tack.

It is evident from the preceding description that the deflector 225 oscillates'once during two consecutive revolutions of the looper. Inamuch as the loop deflector 225 may be interchangeablegears I85, I88 with new gears 230, and 23I (Figs.

12 to 14 inclusive) which have a ratio of 2 to 1.

While it is 'not imperative to make the crankpin I8l"radially..adjustable on the disk I83 as shown in Figs. 12, 16 and 19, because ..a slight variation of the amplitude of oscillation of the needle 49 and a corresponding. variation-of the alternate rotary speeds of the looper will-not ordinarily result in a defective timing of the loop deflector 225, it is nevertheless preferable to make this crank pin I8I adjustable for operating either the bobbin retainer I13 or the loop deflector 225 either one of which may be placed on the rod I10 (Fig. 1) for the formation or look stitches or chain stitches, respectively.

The described mechanism, which may produce either lock stitches or chain stitches, is also particularly adapted for sewing onbuttons having one or more groups or series of holes through which the stitches are to be laid. If a-button with only two holes is to be attached,'the link 20I in Fig. 4a is so adjusted that its connection with the lever 203 within the conflnes of the arcuate groove 202 is in coaxial ,alinement with the pivot 204 so that no longitudinal motion is transmitted to the needle-oscillating bar 53. In this way only the lateral vibration of the needle in a plane at right angles to the needle crank shaft 42 is utilized for laying the jstitches through the two holes of the button. However,

if the button has more than two holes, 1. e., more than one group or series of holes, the needle 34 will have to move laterally in the two transverse directions of which it is capable. However, no step-by-step retracting motion of the needle and of its cooperating thread handling element underneath the work table 32, as caused by the shape of the cam groove 55in Fig.

can be utilized because the stitches through each group of holes must be superposed and cannot progress in a zigzag fashion. Recourse is, therefore, had .to the cam disk 5311 (Fig. 4a) with its cam groove 55', instead of the cam disk 53 (Fig. 4) with its cam groove 55. This groove 55' is designed for the attachment of a button having two pairs of holes as follows from the two diametrically opposite cam portions 235 which are joined by concentric groove portions 231 and 238. While the follower 206 of the lever 203 travels in either of the concentric groove portions 231 or 238, the needle is vibrated in a plane at right angles to the needle crank-shaft 42- and forms a group of superposed stitches through the first group of holes.

On the first cooperation of the follower 206 with a groove portion 235 during the sewing operation, the needle I! and the cooperating thread-handling element underneath the work table 32 are shifted from operative alinement with the first pair of holes of the button into operative alinement with the other pair of holes thereof. The stitches laid through both pairs of holes of the button may either be lock stitches or chain stitches, depending on the use of a shuttle or of a looper. By making appropriate adjustments of the lateral motions of the needle and corresponding adjustments of the alternate speeds of the thread-handling element, the present machine can be used for attaching buttons having differently spaced holes.

While lock stitches do not necessarily require a tying stitch at the end of a sewing operation, chain stitches should terminate in at least one tying-stitch. Hence, regardless of the use to which the present machine may be put, provisions are preferably made in the machine for making a tying stitch at the end of a sewing operation. The present invention is, however, not concerned with the formation of a tying stitch, wherefore neither disclosure is made, nor a description given, of structure for forming a tying stitch.

Any conventional structure may be added to the While it was stated that the present machine can be readily used for sewing on buttons, no eifort is made to disclose certain mechanisms customarily used in button sewing machines. It is deemed unnecessary to show, for instance, a button clamp or a thread severing device, etc.

I claim: 1. In a sewing machine, the combination of a reciprocating and laterally movable needle; a laterally immovable thread-handling element rotatable about an axis transverse to the direction of lateral movement of the needle; and two permanently meshing helical gears rotatable about parallel axes, the driven gear thereof being drivingly connected with said element and one of said gears being axially movable relative to the other gear.

2. In a sewing machine, the combination of a reciprocating needle movable laterally in several axially movable with the needle in one of said lateral directions; means for rotating said element in one direction; and means associated with said rotating means for varying the rotation of said element to advance or retract the beak thereof angularly with respect to its path of retation to such an extent that the leading point of said beak always passes the reciprocating needle at the same distance from the needle point in any lateral position of said needle.

3. The combination in a sewing machine as set forth in claim 2, in which said rotating means includes two permanently meshing helical gears rotatable about parallel axes, the driven gear thereof being drivingly connected with said element, and said associated means includes a device for moving one of said gears axially relative to the other gear.

4. In a sewing machine, the combination of a reciprocating and laterally vibratory needle; a laterally immovable thread-handling element rotatable about an axis transverse to the plane of vibration of the needle; means for rotating said element in synchronism with each needle cycle, said means including two permanently meshing helical gears rotatable about parallel axes and one of said gears being axially movable relative to, the other gear; a first adjustable device for imparting vibrations of variable ampli-.

tude to the needle; and another adjustable device for axially reciprocating said one gear in timed relationwith the needle reciprocation and through such a distance that said element remains in synchronism with the vibrating needle.

5. The combination in a sewing machine as set forth in claim 4, in which said other device includes a pivoted shifter lever for said one gear, a rotary cam, a pivoted follower therefor having an arcuate groove,' and a link having one end pivotally connected with said shifter lever and its other end adjustably pivoted in said groove which is concentric about the pivot connection between said link and shifter lever when the needle is in the middle position of its vibration.

6. The combination in a sewing machine as set forth in claim 4, in which said'first device'is adjustable for imparting to the needle vibrations of an amplitude variable between zero and a preassigned maximum, and said other device is adjustable for reciprocating said one gear through a distance variable between zero and a preassignedmaximum distance.

7. The combination in a sewing machine as set forth in claim 4, in which said first device is adjustable for imparting to the needle vibrations of an amplitude variable between zero and a preassigned maximum, and said other device includes a pivoted shifter lever for said one gear,

'the needle is in the middle position of its vibration range.

8. In a sewing machine, the combination of a reciprocating needle laterally vibrating in one direction and laterally movable in a direction transverse to said one direction; a first rotary shaft axially movable in said transverse direction; a thread-handling element carried by said shaft; means for simultaneously moving said needle and shaft equal amounts in said transverse direction; another shaft parallel to said first shaft and driven in timed relation with the needle reciprocation; two permanently meshing helical gears mounted on said shafts; respectively, for rotation therewith one of said gears being axially movable relative to the other gear; and mechanism for axially reciprocating said one gear in timed relation with the needle vibration and through such a distance that said element is rotated in synchronism with each working cycle of the vibrating needle.

9. In a sewing machine, the combination of a reciprocating needle having a lateral vibration of variable amplitude; a laterally immovable shuttle; adjustable means rotating said shuttle at alternately different speeds so as to maintain its rotation in constant synchronism with the needle reciprocation during vibration of any amplitude; a bobbin case freely rotatable in said shuttle and having a circular groove in its exposed front wall; a bobbin case-retaining member pivoted on an axis concentric to said groove and having two fingers so angularly spaced that at least one is in registry with said groove at all times; and adjustable means rocking said member through a variable angular range so that each finger leaves said groove to provide a gap therebetween through which the passing leg of the needle thread loop travels regardless of the variable alternate rotary speeds oi the shuttle.

, 10. In a sewing machine, the combination of a reciprocating needle movable laterally in one 5 direction: a looper; a combined support and drive for said looper movable axially oi the latter in said one direction; a loop deflector; a shaft carrying said deflector and axially moving together with the combined support and drive in "I said one direction; and means for oscillating said shaft in timed relation with said drive so that the loop deflector may cooperate with the looper in any position 01' the latter. v

11. In a sewing machine, the combination of a 15 reciprocating needle movable laterally in one direction; a shuttle; a removable bobbin case in said shuttle; a combined support and drive for the shuttle movable axially of the latter in said one direction; a shaft oscillatable about its own 20' axis and axially moving together with said combined support and drive in said one direction; a retainer carried by said shaft; and means for oscillating said shaft intimed relation with said drive whereby said retainer cooperates with the bobbin case to retain the same in the shuttle in any axial position of the latter and'permit the complete passage of the thread 0i. a loop on the shuttle between said retainer and bobbin case.

SAMUEL W. AVIS. 

